In the past week, his Twitter messages have been read aloud by his Cabinet ministers at televised events. At one event Friday, Chavez's supporters responded with shouts of "Onward, Comandante!"

In several Twitter messages Saturday, Chavez urged his party to mobilize "toward the big victory of Oct. 7" in the election. Another said: "Comrades you make me happy! Let's keep fighting very hard to defeat the bourgeoisie! A downpour is falling over Havana, and I'm with you!"

Chavez's online messages aim to "make it appear that the president is active, that the president is in control of what's going on in Venezuela," said Jose Vicente Carrasquero, a political science professor at Venezuela's Simon Bolivar University.

Carrasquero, a government critic, said that while Chavez has been coping with illness, long-standing problems such as rampant crime, inflation and sporadic shortages of some food items are going unresolved.

Without Chavez on the air, state television has instead shown a salsa concert, documentaries and a Mass. Such programs and newscasts are interspersed with a short segment showing a healthy Chavez embracing children in slow motion against a background of folk music.

Columnist Fausto Maso wrote in the newspaper El Nacional that "never has the uncertainty been greater in Venezuela."

Pro-Chavez lawmaker Dario Vivas dismissed concerns about Chavez keeping a lower profile, saying the president remains fully in charge and is regaining his health.

"The same people who complain that he talks a lot are the ones who get panicked when they don't hear him," Vivas said.